SALON AV: S.A.Lab Black Knight Reference Amp Set

This super gigantic three-block amplifier set is the ultimate amplification solution unveiled by the Russian manufacturer [S.A. Lab] The mono-block weighs a hefty 275 kg, consuming 400 watts of power obtained entirely on germanium transistors — a challenge that has yet to be accomplished by other manufacturers around the world.

Yes. You heard me right: we have reviewed the design and construction techniques and listened to sound samples on the STUDER A820 tape recorder. Great work, incredible result, incredible sound!

I have written somewhere else that the most serious drawback of amplifiers based on germanium transistors is their inability to achieve high power handling capability. Semiconductors of this type are usually low-voltage, which limits the possible range of the output stages to 25-30 watts. But there is an exception to any rule, and, in this case, it is a circuit called the Circlotron. Its peculiar feature is in its "multi-level", which allows each level to receive power from a separate source, so that the voltage generated by them is added up. That also allows acceleration of the output signal to a very decent amplitude. Needless say that the main disadvantages of this scheme are in its complexity and high cost, especially when implemented at the High End Audio level.

«It's painfully tempting to not leverage the potential of sound inherent in germanium transistors to power up modern low-sensitivity acoustics.»

For Alexey Syomin, the founder of S.A.Lab, neither the final size of the products, nor their costs, seems to be the primary consideration. His credo is, designing good sound system is all that matters, and the cost will take care of itself. This principle spurred him to explore the Germanium theme, having decided to take the circlotron as the basis of his circuit technique. It's painfully tempting to not leverage the potential of sound inherent in germanium transistors to power up modern low-sensitivity acoustics.

And thus was born S.A.Lab's most ambitious project: the Black Knight Reference set, consisting of a pre-amplifier and a pair of 275-kilogram monoblocks. This giant troika retails for 300,000 Euro ($324,402)!

The idea was to maintain the purity of the concept by putting on germanium not only the sound path, but also rectifiers with the entire power system. The stabilizers are built on transistors 1T813A, which are also used in the output stages – there are eight of them in each channel. Germanium power Diode D 304 (16 pieces per monoblock) are equipped with individual cooling radiators. The stabilizers and amplifier boards are mounted on huge vertical heat sinks, the temperature of which is controlled by digital thermometers. Built-in silent coolers are switched on whenever additional cooling is required. The monoblocks are equipped with overload protection and soft starters for smooth charging of filter capacitors with a total capacity of 80,000 uF. The power supply buses are also shunted with proprietary 470 uF film capacitors. They are all mounted on brackets made of artificial stone. All blocks are detachable, on loops and blade connectors, so any malfunctions are detected and treated quickly, usually by replacing the corresponding board.

«Stabilizers and amplifier boards are mounted on huge vertical heat sinks, the temperature of which is controlled by digital thermometers.»

The heat sinks also can slide back, which makes it easy to check modes and ensure that all connections are organized through high-quality blade connectors.

The power amplifiers are mounted on a vertical steel chassis, and the upper and side panels have ventilation shutters. The front panel is made of polished artificial stone with genuine leather finishing. The upper part of the panel is illuminated with the S. A. Lab logo and the company's motto: Nothing but Music. The monoblocks are mounted on specially designed platforms with wheels for ease of movement.

The preamplifier is also assembled on germanium transistors, complete with a balanced signal path and input and output transformers. Individual decoupling buffers are provided for each input (five linear, including 3 Unbalanced on RCA and 2 Balanced XLR). There are three outputs — two on the XLR and one on the RCA. Thus, the preamp features eight expensive broadband transformers for converting a circuit from unbalanced to balanced and vice versa. The volume control is built on relays and Tantalum resistors. An output impedance on the order of 12 ohms makes the preamplifier insensitive to interference from the quality and length of the cables running to the monoblocks. For listening, our entire system was switched to balanced cables, which are also produced by Syomin's laboratory.

The speaker systems used are ProAc Carbon Pro 8, and, as a source, we also used the Studer A820 Studio master recorder, which was specially brought to the Nota Plus salon for the test. All phonograms (copies from master tapes) were recorded on two tracks at the rate of 38 cm/s.

«The feeling of colossal, unrestrained freedom of musical reproduction with a typical "germanium", almost lamp-like character is, to tell you, quite overwhelming.»

We set out to experience an unlimited sound dynamics, and we heard it in all its glory. The feeling of colossal, unrestrained freedom of musical reproduction with a typical "germanium", almost lamp-like character is, to tell you, quite overwhelming. I do listen to 2 X 15w germanium amplifier stereo at home, and here too, I'm listening to the same sound, albeit shrank into the chair feeling the sound pressure. By "the same sound," I mean soft in the upper range, rich in the lower range and with a sparkling clean, very comfortable middle. A pair of Black Knight Reference amps delivers completely unrealistic attacks, instantly reacting to sharp changes in the punchy rhythm and, most importantly, making the acoustics do the same. Never heard these multipath ProAkis sang so beautifully and smoothly. There is absolutely no hint of synthetics in the sound — every instrument, every sound is transmitted with a natural spectral content. At first it seems that the familiar soundtracks have become more nuanced, but in fact they are just transmitted somehow more clearly. And at the same time, musically, without being mechanical. I should add that it's nice and elegant, with a unique charm that persists even at such volumes, when the acoustically treated room starts to respond.

The amplifier ably demonstrates very subtle intonation and shades of meaning, underscoring its outstanding strength of steel and velvet and shock power. And this delivery is surprisingly universal – the system has preserved the manner of delivery on any music, from Michael Jackson to Led Zeppelin and BSO. I immediately remembered the words of Flemming Rasmussen from Gryphon Audio: "If the amp doesn't play all genres, then there's something wrong with it." With the Black Knight Reference, you can forget about such problems — these giants boast everything to cause a culture shock for any music lover, regardless of age and musical preferences. If you want a wall of sound, you will have a wall; if you want a violin with all the details, you will have a violin. Just pick up decent high-resolution speaker system that can withstand such pressure. And, surprisingly, amplifiers do not need time to play out — they show all the features of their character once they are switched on. This indicates the correct circuitry and optimal power management.

«The amplifier ably demonstrates very subtle intonation and shades of meaning, underscoring its outstanding strength of steel and velvet and shock power.»

Yes, the amp set isn't cheap. But in High End audio, as in big sports — the greater the performance, the more effort is needed to improve on it. In recent years, I had the opportunity to listen to many amplifiers made by Alexey, and some of them wowed me as impeccable products in terms of sound quality. Yet the Black Knight Reference stands out as noticeably superior to all of them, demonstrating an extremely attractive combination of qualities. And against this background, I dare say that the asking price for the amp set no longer seems prohibitively high.

Amplifier type: push-pull, class AB || Output Power: 400 W (4 Ohms) || Frequency range: 2 Hz — 200 kHz || Nominal sensitivity: 800 mV || Input Impedance: 47 kOhm (RCA), 25 kOhm (XLR) || Signal to Noise Ratio: -103 dB || Distortion level: 0.05% (50 W, 4 Ohms, 1 kHz) || Inputs: XLR, 4 x RCA, bypass RCA || Maximum power consumption: 460 VA || Dimensions (W x H x D): 480 x 310 x 505 mm || Weight: 275 kg || Price per set: 300,000 Euro (converted from rubles).

The editors would like to thank the Nota + Salon for their help in conducting the audition.